[4] It is not always necessarily an audible phrase, though; for example, The Neptunes' signature "four-count start" and Lex Luger's "synth crescendo" may also be considered producer tags.
[5][6] Some contemporary hip hop music producers who are famous for their tags include Metro Boomin, DJ Khaled, Mike WiLL Made-It, Harry Fraud, Tay Keith, Take a Daytrip, J. R. Rotem, Murda Beatz, JetsonMade, and Wheezy, among others.
Producer tags originated in the 1990s, when hip hop music was beginning to get significant mainstream attention, when it was commonplace for rappers to loudly announce their names over the instrumentals, which was known as ad-libbing.
They were initially used as a form of protection against somebody stealing the beat; the musical equivalent of an artist signing their art.
It began being used as a sort of slogan with the intention of making sure the listener knows and remembers, consciously or subconsciously, who is responsible for the music's production.